Telephone alarm system



Feb. 26, 1935. J ER' 1,992,255

TELEPHONE ALARM SYSTEM Filed Oct. 24, 1933 A J )4 INVENTORI 4- A TTORNEYPatented Feb. 26, 1935 11mm STATES PATENT OFFICE TELEPHONE ALARM SYSTEMJohn I. Swadener, Greenville, Ohio Application October 24, 1933, SerialNo. 694,945

3 Claims. (01. 179-5) This invention relates to new and usefulimprovements in telephone alarm systems.

In residence, omce and factory buildings equippedwith telephonesconnected to a central station, it is highly desirable that the electriccircuits including these instruments be adapted for use to operate atcentral, signals indicating unauthorized entries, fires and otheremergencies in those structures.

It is the principal object of my invention, therefore, to provide forassociation with a telephone circuit, means for using that circuit in anemergency, to automatically actuate at the central station, a visible oraudible signal having a designation corresponding to the location of thetelephone in the building or room being broken into by an unauthorizedperson, or in which a fire or other emergency has occurred.

My alarm system, which is simple and emcient, may be adapted to anyexisting telephone system for protecting houses or other buildingsparticularly against the entry of burglars. By means of a switch placedin a convenient, and preferably concealed, location, the telephoneinstrument may be automatically shorted out of the circuit while thelatter is used to operate at the central station, a signal bearing thedesignation corresponding to the location of the telephone. After thesignal is given, a relay may be easily reset to restore the signalcircuit to its normal operating condition.

Other important and incidental objects will be brought out in thefollowing specification and particularly set forth in the subjoinedclaims.

In the accompanying drawing, the figure is a schematic diagram of mytelephone alarm system.

Referring to the drawing, the numeral 1 desig nates the pair of asubscribers telephone circuit which leads from a telephone 2 to acentral switchboard 3. shunted across the line 1 is a fixed resistance 3and a push button switch 4 by which a fixed resistance may be placedacross the line, decreasing the normal resistance of the telephoneand'resulting in a drop in the line voltage.

At central there is provided for each subscribers telephone, ifdesiredfa relay 5 having dual windings 6 and 7, the winding 6 beingshunted across the telephone line 1 by lines 8. When the normal fullvoltage flows through the telephone, the voltage impressed onthe winding6 of the relay 5, will hold the relay armature 9 away from a contact 9,in opposition to the tension of a coil spring 10, and in engagement withthe pole piece. 7

If the switch 4 is momentarily closed by one who is aware of theentrance of an unauthorized person into the building, the drop involtage in 5 the line and through the winding 6 by reason of theconsequent insertion of the resistance 3 in the telephone circuit, willrelease the relay armature 9 which will then be drawn by the spring 10into engagement with the contact 9'. 10 The latter is in a secondarycircuit 11 that also includes a signal lamp 12 on ,an auxiliary board13, and a battery 14. When-the contact 9 is engaged by the relayarmature, it will close the secondary circuit including the signal lamp12 15 identifying the particular subscribers telephone from which thesignal is received, to illuminate that lamp. The exchange operator incharge of the auxiliary signal board 13, being apprised, by theillumination of a signal lamp designating a particular subscriberstelephone, that some emergency exists at the location of it, willimmediately inform the proper authorities.

While any number of relays and associated signal lamps may be providedat central, I have illustrated in the drawing, four relays 5 shuntedacross respective subscribers telephone linesat the central switchboard3, by lines 8. The armature of each relay will be held away from itsrespective contact 9 as long as the normal full -30 voltage flowsthrough its respective telephone circuit, but will close the secondarycircuit, as before described, to illuminate an identifying lamp in thatcircuit when the switch 4 is actuated to cause a voltage drop in thetelephone line.

For the purpose of resetting a relay 5 after a signal lamp has beenilluminated, I have pro-' vided the following means that are conmion toall the relays. The winding '7 of each relay is connected through acommon lead 15 and a switch 16 with the battery 14. When the switch 16is closed by the operator, the winding 7 of the relay 5 belonging to atelephone line over which an alarm has been sent, will retract thearmature 9 into engagement with the pole piece, in which position itwill be held by the normal telephone line voltage now impressed on thewinding 6. Thus itis possible by the above, or other suitable means,forthe operator to easily reset a relay 4 to break the secondary signalcircuit and restore the armature to its normal position for operation bythe spring 10 to again close the secondary circuit to illuminate theidentifying lamp included therein when a drop in the telephone linevoltage is effected by the operation of theswitch 4. This switch may beplaced on or in a desk, under a counter or in any other convenientlocation for quick, silent and concealed operation by one who isapprised of the entrance oi an unauthorized person.

It is thus seen that my signaling means may be applied to any existingtelephone system foruse in protecting subscriber's homes, oilices,plants andother buildings against the entrance 01' unauthorized personsas well as for use in fires and other emergencies. For example, my alarmcircuit may. be connected to the subscriber's line between thesubstation and the central station in the circuit illustrated anddescribed on pages 306-309, of Telephone and Telegraph EngineersHandbook, 1st Edition, 48th Thousand, 11th Impression, by InternationalCorrespondence Schools, Scranton, Pennsylvania, and published byInternational Textbook Company of Scranton, Pennsylvania. I

I do not wish to be limited to the details of constructionandarrangement herein shown and described, and any changes or modificationsmay be made therein within the scope of the subjoined claims.

Having described nrv invention, I claim:

1. An apparatus of the type described, comprising a telephone line, atelephone in said line, a circuit including a switch and a resistanceshunted across the telephone'endoi said line, a centralswitch board towhich the other end said telephone line is-connected, a'second circuitshunted across the switch board end or said tele phone line, a relay inthe second circuit, and a signal circuit also including said relay, thearmature of said relay adapted to be held against the pole piece by the'normal voltage in the telephonev a circuit including a switch and aresistance shunted across the telephone end of said line, a centralswitchboard to which the other end. or said telephone line is connected,a second circuit shunted across the switchboard end of said telephoneline, a relay having a dual winding, the outer winding being included inthe second circuit, a signal circuit also including the outer winding,the armature of said relay adapted to be held against the pole piece bythe normal telephone line voltage impressed upon the outer winding, acontact in the signal circuit opposite the free end of said armature, aspring adapted to draw said armature away from the pole piece andagainst the contact to close the signal circuit when the switch isactuated to eflect, through the resistance, a drop in the voltageimpressed upon the outer winding of said relay, and means for impressingvoltage on the inner winding to draw the armature away from the contactto break the signal circuit, and into engagement with the pole piece, toreset the relay.

3. An apparatus of the type described, comprising a telephone line, atelephone in said line, a circuit including a switch and a resistanceshunted across the telephone end of said line, a central switchboard towhich the otherend of said telephone line is connected, a second circuitshunted acrtms the switchboard end of said telephone line, a relayhaving a dual winding, the outer winding being included in thesecondcircuit, a signal circuit also including the outer winding, the armatureof said relay adapted to be held against the pole piece by the normaltelephone line voltage impressed upon the outer winding, acontact in thesignal circuit opposite the free end of said armature, a spring adaptedto draw said armature away from the pole piece and against the contactto close the signal circuit when the switch is actuated to eil'ect,through the resistance, a drop in the voltage impressed upon the outerwinding of said relay, and a circuit including a switch, a battery andthe inner winding or the relay for resetting the latter.

JOHN I. SWADENER.

